Hermetically sealed relay having high and low voltage contact assemblies in a common chamber



INVENTOR. JACK s. HAWKINS J. S. HAWKINS CONTACT ASSEMBLIES IN A COMMON CHAMBER Filed Nov. 29, 1963 HERMETICALLY SEALED RELAY HAVING HIGH AND LOW VOLTAGE Sept. 27, 1966 United States Patent Office 3,275,775 Patented Sept. 27, 1966 3,275,775 HERMETICALLY SEALED RELAY HAVING HIGH AND LOW VOLTAGE CONTACT ASSEMBLIES IN A COMMON CHAMBER Jack S. Hawkins, San Jose, Calif., assignor to Jennings Radio Manufacturing Corporation, San Jose, Calif., a corporation of Delaware Filed Nov. 29, 1963, Scr. No. 326,960 7 Claims. (Cl. 200-144) This invention relates to relays, and particularly vacuum relays.

One of the objects of the invention is the provision of an electromagnetically operated relay incorporating --a single pole, single throw high voltage relay and a single pole, double throw low voltage relay in a single evacuated envelope.

Another object of the invention is the provision of a high voltage grounding relay incorporating contact structures having low emission characteristics.

A still further object of the invention is the provision of a unitary light weight relay having enclosed contacts of low mass inherently resistant to shock and vibration and therefore especially useful in environments where these are important factors.

Still another object of the invention is the provision of a relay of the character described designed for economical manufacture by production line techniques.

The invention possesses other objects and features of advantage, some of which, with the foregoing, will be apparent from the following description and the drawings. It is to be understood however that the invention is not limited by the description and the drawings, but may be embodied in various forms within the scope of the appended claims.

Broadly considered, the relay of the invention comprises an electromagnetic actuating section, a low and high voltage contact section and a high voltage terminal section, the various sections being integrally interconnected in end-to-e nd relation to provide a hermetically sealed envelope. The electromagnetic actuating section includes a metallic housing adapted to be held at ground potential, and includes a coil surrounding a magnetic core extending into the envelope. Within the contact section of the envelope, the relay is provided with a central stem on one end of which is secured a floating armature cooperatively related t-o the adjacent end of the magnetic core to effect axial displacement of the central stem. Spaced along the stem are radially extending movable resilient contact members of low mass having contact surfaces adjacent their free ends. Alternately interposed between such movable contact members are additional radially extending contact fingers also of low mass adapted to be engaged and disengaged by the movable resilient contact members. Means are provided to connect and disconnect the high voltage terminal section with the grounded electromagnetic housing section through the movable resilient contact members. Means are also provided encapsulating the body of the relay to increase the exterior voltage break-down path of the relay, and make the relay more resistant to impact shocks.

Referring to the drawings:

FIG. 1 is a vertical cross-sectional view through the central axis of the relay.

(FIG. 2 is a bottom end view of the relay.

FIG. 3 is a horizontal cross-sectional view taken in the plane indicated by the line 3-3 in FIG. 1.

In terms of more specific detail, the grounding relay of the invention comprises an electromagnetic actuating section designated generally by the number 2, including a ferromagnetic hollow cylindrical portion 3, having a non-magnetic transverse wall 4 hermetically interposed intermediate its ends and forming a part of the evacuated envelope. The wall serves to support a centrally disposed magnetic core 6 having an enlarged head portion 7 at its inner end. At its outer end the core is provided with a threaded extension 8 to which is detachably secure-d a ferromagnetic cover plate 9 on which is mounted a coil 12. As shown in FIG. 1, the enlarged head portion 7 of the magnetic core lies substantially flush with the inner end of the cylindrical housing 3 for purposes which will hereinafter be explained.

Axially aligned and hermetically united to the electromagnetic actuating section 2 is a hollow cylindrical dielectric-metallic contact section designated generally by the numeral 16. This section preferably comprises a multiplicity of axially aligned and appropriately metalized ceramic ring members .17, 18, 19, 21, 22 and 23. Interposed hermetically between adjacent ceramic rings are pairs of juxtaposed metallic rings .24 and 26 respectively. The metallic rings positioned between ceramic members 17-18, 18-19, 19-21, and 21-22 are each provided with an external radially extending terminal section 27 connected by an appropriate lead 28 to an insulated terminal 29 or a grounded terminal 29 supported on flange -31 as shown. The external terminal tabs 27 are circumferentially spaced about the outer periphery of the contact section. It will of course be obvious that the terminals 29' may or may not be grounded to the flange 31.

The adjacent metallic ring 26 of each pair of rings 24- 26 caught between ceramics 17-18 and 19-21 is electrically connected to the ring 24 and is provided with a radially inwardly extending low mass resilient finger portion 32 t-erminating within the hollow contact section intermediate the inner periphery of the contact section and the central axis of the relay in a domed contact portion 33. It will of course be understood that the ceramic rings and the metallic rings are stacked in axial alignment and hermetically brazed into a rigid composite structure as shown.

Intel-posed between ceramic member 18-19 is an additional metallic ring 26' differing somewhat from the corresponding ring members 26 between ceramic rings 17-18 in that the resilient spring finger portion 32 is lengthened so as to extend past the central axis of the relay and terrninates in a flat contact portion 34 adapted to make and break electrical contact with opposed dome-shaped contact members 33 as shown. The manner in which spring finger 32' is caused to flex or move between the opposed domed contact members 33 will hereinafter'be described.

Ring member 26' interposed between ceramic members 21-22 is similar to the corresponding ring member 26 interposed between ceramics 18-19 except that in this instance the portion of the spring finger 32 which extends past the central axis of the relay is provided on its free end with a domed contact portion 36 as shown instead of a flat contact surface as at 34.

As will be obvious from the drawing, when the foregoing assembly of ceramic and metallic ring members are assembled and brazed into a composite unit, the assembly constiutes a rigid separate .subassembly which may be effectively vacuum leak-checked and the contact clearance adjusted before hermetically uniting this subassembly to the electromagnetic actuating section 2. Such interconnection is accomplished by a cylindrical shelllike metallic member 37, flanged and brazed at one end to the adjacent previously metalized end of ceramic member 1'7, and flanged and heliarc welded at its other end to an appropriate flange 38 extending radially from the housing 3. Appropriate external tabs 27 integral on selected metal ring members facilitate connection of the relay into a circuit.

Within the hollow contact section 16 is a magnetizable floating armature 39 arranged to move axially with respect to the core to complete the magnetic circuit between the core core and housing when coil 12 is energized. Movement of the armature toward the core is opposed by coil spring 41 interposed between the underside of the armature and the non-magnetic wall 4.

To actuate the movable resilient contact fingers 32 which extend past the central axis of the relay, a stem structure is mounted on the armature and comprises a centrally disposed metallic rod 42 supporting dielectric spacer elements 43 engaging the spring fingers 32 intermediate their ends as shown. The stem assembly is held together by an appropriate nut 44. It will thus be seen that when the coil is energized the armature is pulled down against the core and housing, thus displacing or flexing the movable spring fingers so that flat contact portion 34 and domed contact 36 change their relationship to adjacent relatively fixed domed contacts.

The high voltage terminal section 46 of the relay includes an elongated tubular ceramic section 47 having an annular end plate 48 at its end adjacent the hollow contact section provided with a cylindrical metallic sealing flange 49 heliarc welded to cylindrical metallic shell 51. The other end of the shell is brazed to ceramic ring 22 as shown. The annular end plate 48 is hermetically and flexibly united to the tubular ceramic 47 by a cylindrical metallic sealing ring 52 as shown.

At its other end the tubular ceramic 47 is closed by an annular end plate 53 hermetically and flexibly united to the tubular member 47 by a metallic sealing ring 54 as shown. Ceramic backup rings 56 and 57 are slidably interposed between end plates 48 and 53, respectively, and the adjacent ends of the tubular ceramic 47 in order to support the hermetic union between these members and to facilitate accommodation of differences in thermal expansion and contraction between the ceramic and metallic parts.

Centrally disposed and hermetically mounted on the end plate 53 is a metallic tube 58 extending coaxially with respect to the ceramic member 47 and terminating within the envelope in a free end portion 59, which has resiliently mounted thereon a high voltage fixed contact member 61 adapted to make and break contact with the high voltage movable contact member 36.

At its other end tube 58 provides a tubulation 62 through which the envelope may be evacuated and which may be pinched ofl. as shown to seal the envelope. A protective cap structure 63 is brazed to the end plate surrounding the pinched-oil end of the tabulation to protect the tubulation, and to provide a conductive path between the tube-end plate assembly and the terminal member 64. Connection to the terminal member may be made by any suitable means such as a screw 66.

It will thus be seen that the high voltage terminal 64 is spaced a considerable distance from any structure which is at ground potential, thus providing a long voltage breakdown path on the outside of the envelope. Within the envelope the high voltage fixed contact 61 is appropriately related to the high voltage movable contact member 36 so as to provide the necessary vacuum insulation between these members when the coil is energized.

It will of course be understood that in the normal operation of the relay, the relay will be interposed as a protective element in a circuit so that interruption of the electric current in the circuit will also deenergize the solenoid coil 12 and result in making contact between contacts 36 and 61 so as to connect the high voltage terminal to ground. Domed contacts 33, which are resiliently engaged and disengaged by flat movable contact 34, constitute low voltage fixed terminals conveniently connected to indicator lights and the like useful to visually indicate a condition in the circuit.

To protect the envelope against impact shocks, and to provide an increased voltage break-down path over the exterior of the envelope, the envelope is preferably encapsulated within a body 67 of high dielectric strength silicone rubber as shown. At one end the encapsulating body of rubber is confined by the mounting flange 31, and at its other end is formed to surround the tubulation and a portion of the high voltage terminal. The rubber body may be corrugated around its exterior to further increase the length of the electrical path between the high voltage terminal and ground.

I claim:

1. A relay comprising an hermetically sealed hollow envelope including a high voltage insulator section, a contact section, and an actuator section axially aligned and disposed endto-end in hermetically sealed relation, said high voltage insulator section comprising an elongated tubular dielectric portion having one end hermetically united to the contact section and an end plate closing the other end, a high voltage contact assembly within the contact section including fixed and movable contacts, a low voltage contact assembly within the contact sec. tion including fixed and movable contacts, and actuator means within the actuator section including a central stem engaging the movable contacts of the high and low voltage contact assemblies to effect make and break operation thereof in unison.

2. The relay according to claim 1, in which the contact section comprises a plurality of alternately arranged axially aligned hermetically united metal and ceramic rings.

3. The relay according to claim 1, in which said high voltage contact assembly includes an elongated tubular conductor extending coaxially through the tubular dielectric portion to support the fixed high voltage contact on its inner end, and the movable high voltage contact is supported on the envelope contact section and is movable by the actuator means into and out of engagement with the fixed high voltage contact.

4. The combination according to claim 2, in which the low voltage contact assembly includes a spaced pair of low voltage fixed contacts mounted on spaced metallic rings. of the contact section, each fixed contact including a radially extending resilient finger portion integral at one end with the associated ring and at its other end provided with a contact surface, and a low voltage movable contact movable between said spaced pair of fixed contacts to make and break a circuit between said movable contact and one of said low voltage fixed contacts.

5. The relay according to claim 1, in which a mounting flange is provided supported on the actuator section of the envelope, and said high voltage movable contact is electrically connected to the mounting flange whereby when the high voltage contact assembly is closed to make a circuit therethrough the high voltage fixed contact is electrically connected to ground through said mounting flange.

6. Therelay according to claim 1, in which a mounting flange is provided supported on the actuator section of the envelope, and a low voltage fixed contact is electrically connected to the mounting flange whereby when the low voltage fixed contact is engaged by the low voltage movable contact a circuit is completed through the mounting flange.

7. A high voltage grounding relay comprising an hermetically sealed hollow envelope including a high voltage insulator section, a contact section and an actuator section axially aligned and disposed end-to end in hermetically sealed relation, a high voltage contact assembly comprising an elongated tubular conductor extending ooaxially through the high voltage insulator section and supported thereon, a fixed high voltage contact supported 'on the inner end of the elongated tubular conductor,

a movable high voltage contact supported on the envelope contact section and movable into and out of engagement with the fixed high voltage contact, and actuator means within the actuator section including a central stem engaging the movable high voltage contact and operable to effect make and break operation thereof.

References Cited by the Examiner UNITED STATES PATENTS 2,870,298 1/1959 Schwager 200-144 3,154,655 10/1964 Hawkins 200144 10 ROBERT K. SCHAEFER, Primary Examiner.

KATHLEEN H. CLAFFY, Examiner.

P. E. CRAWFORD, Assistant Examiner. 

7. A HIGH VOLTAGE GROUNDING RELAY COMPRISING AN HERMETICALLY SEALED HOLLOW ENVELOPE INCLUDING A HIGH VOLTAGE INSULATOR SECTION, A CONTACT SECTION AND AN ACTUATOR SECTION AXIALLY ALIGNED AND DISPOSED END-TO-END IN HERMETICALLY SEALED RELATION, A HIGH VOLTAGE CONTACT ASSEMBLY COMPRISING AN ELONGATED TUBULAR CONDUCTOR EXTENDING COAXIALLY THROUGH THE HIGH VOLTAGE INSULATOR SECTION AND SUPPORTED THEREON, A FIXED HIGH VOLTAGE CONTACT SUPPORTED ON THE INNER END OF THE ELONGATED TUBULAR CONDUCTOR, A MOVABLE HIGH VOLTAGE CONTACT SUPPORTED ON THE ENVELOPE CONTACT SECTION AND MOVABLE INTO AND OUT OF ENGAGEMENT WITH THE FIXED HIGH VOLTAGE CONTACT, AND ACTUATOR MEANS WITHIN THE ACTUATOR SECTION INCLUDING A CENTRAL STEM ENGAGING THE MOVABLE HIGH VOLTAGE CONTACT AND OPERABLE TO EFFECT MAKE AND BREAK OPERATION THEREOF. 